In a large heavy-bottomed pot, melt 2 tablespoons of butter over medium heat. Add thinly sliced onions and stir to coat them in the melted butter. Cook for 30-40 minutes until caramelized.

Once the onions are caramelized, remove them from the pot and set aside. In the same pot, add diced bacon and cook over medium heat until crispy, about 6-8 minutes.

Add 1 cup of arborio rice to the pot with the bacon fat, stirring continuously for 2-3 minutes until slightly translucent.

Begin adding hot chicken or vegetable broth, one cup at a time, stirring gently. Allow each addition to be absorbed before pouring in the next.

Once the rice is al dente, stir in the reserved caramelized onions, crispy bacon, and 1/2 cup of grated Parmesan cheese. Add an additional tablespoon of butter and mix until well combined.

Taste and adjust seasoning with salt and pepper. Serve immediately, garnished with extra Parmesan and remaining bacon bits.